山东深秋一次暴雪过程雪水比影响因子分析

Analysis on influencing factors of snow-to-liquid ratio duringa late-autumn snowstorm in Shandong

利用地面气象观测站资料、加密地面观测资料和欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts, ECMWF)第五代大气再分析数据(ECMWF Reanalysis v5,ERA5;分辨率为0.25°×0.25°)逐小时资料,对山东2021年11月6—8日极端暴雪过程雪水比影响因子进行研究。结果显示:此次暴雪过程平均雪水比分布总体呈“北大南小、西大东小”的分布特征,降雪初期产生的雪水比小,降雪中后期产生的雪水比大;温度偏高、云内液态水含量较高的地区雪水比较小,温度偏低、云内液态水含量较低的地区雪水比较大;雪水比与地面气温、地表温度呈负相关,地面气温与雪水比的相关性最大,积雪产生之后地表温度与雪水比变化无明显相关。

The influencing factors of snow-to-liquid ratio(SLR)during a snowstorm in Shandong from 6 to 8 November 2021 are analyzed by using the data of ground meteorological observation stations,intensive ground observation data,and ECMWF(European Centre for Medium-Range Weather Forecasts)Reanalysis v5(ERA5)hourly data(0.25°×0.25°).The results are as follows.The distribution of mean SLR in this snowstorm process is generally characterized by high in the north but low in the south,high in the west but low in the east.The SLR in the early period of the snowfall is relatively low,while it is relatively high in the middle and late period.The SLR is lower in the area with higher air temperature and higher specific cloud liquid water content than that in the area with lower air temperature and lower specific cloud liquid water content.The SLR is negatively correlated with the surface air temperature and surface temperature.The correlation between surface air temperature and SLR is the largest.After snow blankets the ground,the surface temperature has no significant correlation with the change of SLR.